package com.heng.test1;

import java.util.HashMap;
import java.util.Map;

public class Test1 {
    public static void main(String[] args) {
        Map<Integer, Integer> map = new HashMap<>();

        Integer i = map.putIfAbsent(1, 1);

        System.out.println(i);

        System.out.println("pr");
    }
}
